Capacity grew by more than 7.6 gigawatt (GW), breaking the previous records of 7.5GW in 2011 and 7.4GW in 2010, and far above the 2.5- to 3.5GW Berlin would like to see each year.

The solar boom has been encouraged by generous feed-in tariffs, which are guaranteed to generators for 20 years to encourage carbon-free power to gradually replace fossil fuels.

But renewable energy has become politically divisive as businesses complain the shift away from nuclear power towards subsidised renewables is adding to consumer costs and jeopardising economic growth.

The government agreed last year to cut the level of feed-in tariffs – the industry's lifeblood as long as solar power is more expensive than conventional forms of energy to produce – in order to reduce the pace of installations.

Tariffs were cut by 2.5% a month between November 1 2012 and January 31.

Installation decrease
An Environment Ministry spokesperson said installed capacity in the last quarter of 2012 was less than a fifth of overall installations last year.

He said 611 megawatts (MW) had been installed in October, 435MW in November and 360MW in December. "This shows that the amendment is working," he said.

The ministry expects new solar power generating capacity of between 3.5- and 4GW in 2013.

The share of renewable subsidies within the overall power bill rose 47% on January 1 to 5.3 cents a kilowatt hour, raising the subsidising cost per average household by 60 euros to 185 euros for the year.

Private consumers bear the brunt of the costs of renewable energy subsidies after the government gave breaks to energy-intensive industry, cutting some of the green energy and network usage costs for companies.

The association of solar producers said on Tuesday its members supplied 8-million households with power, 45% more than in 2011 – accounting for 5% of total power usage.
– Reuters